Container having rectangular base and its manufacturing

ABSTRACT

A container is constructed from a pouch having a front sheet, a rear sheet and a bottom sheet. The bottom sheet of the pouch is folded along a midline thereof with flaps extending downward from the fold line. Each of the bottom edges of the flaps are welded to or integral with one bottom edge of either the front or the rear sheet. Lateral edges of the front and rear sheets are welded to one another with the bottom two portions of the welded edges sandwiching both lateral edges of the bottom folded sheet. To construct the container, a central portion of the bottom sheet is unfolded such that the unfolded portion has an essentially rectangular shape, thus forming said base, with central parts of the bottom edges of the bottom sheet forming the front and rear edges of the base and with peripheral portions of the bottom sheet forming two overlapping triangular portions with the bottom edges thereof defining the two side edges of the base. The container&#39;s front and rear wall sections extend from the front and rear edges and side walls extend from the side edges, with the welded edges of the front and rear sheets being at about the midline of the side walls. The structure is fixed by welding the two overlapping triangular portions to one another or by welding a peripheral triangular portion of the two overlapping ones to a juxtaposed inner face of the side sheets.

This is a continuation of U.S. patent application Ser. No. 08/666,279filed Jun. 20, 1996, now U.S. Pat. No. 5,772,332 which is a 371 ofPCT/US95/12264 filed Oct. 2, 1995.

FIELD OF THE INVENTION

The present invention is related to a container having a rectangularbase and it concerns also a method for manufacturing same. By using theterm “container” it is referred to a container manufactured of sheets orfilms of flexible material formed into a suitable shape useful forcontaining unitary items, powdered or granulated material or liquids.

BACKGROUND OF THE INVENTION

Containers with which the present invention is concerned are a practicaland cheap way for packing goods and are thus very common in the foodindustry although not restricted to that field. The major advantages ofcontainers are that they are easy to manufacture, cheap and are usuallysuitable for holding a variety of products. Such containers requireminimal space in storage and are easily disposed of.

The most used form of container is the so-called “pouch” which is asheet of material, e.g. paper, cardboard, plastic or a laminate formedinto the shape of a bag or sack.

In some cases pouches are integrally formed with a base. However, suchpouches are not self-standing and they require the internal pressure oftheir contents for stability. Furthermore, such pouches are usually ovaland are thus less stable and also require more storage space. Stillanother drawback is that the structure of such products is not firm andthus they may collapse when they are not completely full.

In the present description and claims, the terms “heat weldablematerial” or “heat weldable surface” are used for determining layers ofplastic material, e.g. polyethylene, polypropylene, etc. which, uponheating melt and may then be adhered to other such layers by a processwhich hereinafter in the specification will be referred to as “welding”.The term “heat weldable” is also referred to in the art as “heatsealable”.

Typical containers are made of a single sheet folded into a container'sshape with overlapping portions which are then glued or welded to oneanother. Such containers are usually not suitable for containing liquidsand do not have a rigid structure whereby they collapse when theircontents are partially withdrawn. Furthermore, containers manufacturedaccording to the heretofore known methods are usually restricted topouch or prismatic box-like containers.

It is an object of the present invention to provide a novel and improvedcontainer and a process for manufacturing same in which theabove-referred to disadvantages are substantially reduced or overcome.

SUMMARY OF THE INVENTION

According to the present invention there is provided a container madeessentially of one or more film sheets, the container having a bottombase and walls extending upwardly therefrom; the base being essentiallyrectangular and defining front, rear and two side sections of the walls;the base being made of a film with both of its faces being heat weldableand the walls being made of a film having at least an inner heatweldable face; the container being constructed from a pouch having afront, rear and bottom sheet; the bottom sheet of the pouch being foldedalong a midline thereof with flaps extending downwards from the foldline and each of the two bottom edges of the flaps being welded to orintegral with one bottom edge of either the front or the rear sheet,lateral edges of the front and rear sheet being welded to one anotherwith the two bottom portions of the welded edges sandwiching bothlateral edges of the bottom folded sheet; for construction of thecontainer, a central portion of the bottom sheet is unfolded such thatthe unfolded portion has an essentially rectangular shape thus formingsaid base, with central parts of the bottom edges of the bottom sheetforming the front and rear edges of the base and with peripheralportions of the bottom sheet forming two overlapping triangular portionswith the bottom edges thereof defining the two side edges of therectangular base, thereby forming the container's front and rear wallsections extending from said front and rear edges and side wallsextending from said side edges with the welded edges of the two sheetsbeing at about the midline of the side walls; the structure being fixedby welding the two overlapping triangular portions to one another or bywelding a peripheral triangular portion of the two overlapping ones to ajuxtaposed inner face of the side sheets.

According to one embodiment of the present invention the bottom base andthe walls are produced of an integral film sheet having both facesthereof heat weldable.

In order to impart rigidity to the container according to the presentinvention, one or more reinforcement elements made of or coated with aheat weldable material is welded to the bottom face of the rectangularbase and welded thereto. The reinforcement element may be constructed ofseveral segments or may be a uniform frame, welded to the inner face ofthe walls adjacent their top or bottom edges.

A reinforcement element welded to the top may have a shape and sizecorresponding to that of the rectangular base whereby a rectangularbox-like container is obtained. Alternatively, the reinforcement elementmay be of any other shape or size. If the reinforcement element is arectangle larger than the base then a truncated square pyramid isacquired, suitable for stacking such containers within one another.

According to still another embodiment of the present invention, stiffelongate ribs made of or coated with a heat weldable material are weldedalong the internal walls of the container so as to impart rigiditythereto. Alternatively, the stiff ribs are formed integrally with one ormore reinforcing elements. Said stiff ribs may have different shapes sothat when they are welded to the walls the container obtains a shapecorresponding to that of said ribs.

The present invention further provides a process for the manufacture ofa container, the container having an essentially rectangular base withwalls, consisting of a front, rear and two side sections extendingupwardly therefrom, the base being made of a film with both of its facesbeing heat weldable and the walls being made of a film having at leastan inner heat weldable face; the process comprises:

(a) preparing a pouch having a front, rear and bottom sheet, the bottomsheet being folded along a midline thereof with the flaps extendingdownwards from the fold line and the two bottom edges of the flaps beingeach welded to or integral with a bottom edge of either the front or therear sheet, lateral edges of the front and rear sheet being welded toone another with their bottom portions sandwiching both lateral edges ofthe bottom sheet;

(b) unfolding a central portion of the bottom sheet such that theunfolded portion assumes a rectangular shape and each of the twoperipheral portions form two overlapping triangular portions;

(c) welding the two overlapping triangular portions to one another orwelding a peripheral triangular portion of the two with juxtaposed innerface of a juxtaposed sheet.

Another aspect of the present invention concerns continuous processesfor preparing pouches useful in continuous manufacture of containersaccording to the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For better understanding, the invention will now be described by way ofexample only, with reference to the accompanying drawings, in which:

FIG. 1 is an exploded isometric view of the constituents of a basiccontainer according to the present invention positioned according to afirst step of its manufacture;

FIG. 2 is an isometric view of a pouch manufactured according to thepresent invention;

FIG. 3 illustrates how the rectangular shape of the base is obtained;

FIG. 4 is a schematic illustration of the welding process of therectangular base;

FIG. 5 is an isometric view of a basic form of a container according tothe present invention;

FIG. 6 is an exploded isometric view of only a bottom portion of acontainer according to the present invention and a reinforcementelement;

FIG. 7 is a schematic illustration of how the reinforcement frame ofFIG. 6 is welded to the rectangular base of the container;

FIG. 8 is an isometric view of a container according to the presentinvention in which the top edges of the front and rear walls are weldedso as to seal the container;

FIG. 9 is an isometric view of a container according to the presentinvention in which the top edges of the side walls are welded so as toseal the container;

FIG. 10 is a side elevation of the container of FIG. 9;

FIG. 11 is an exploded isometric view of only a top portion of acontainer according to the present invention and a reinforcement frame;

FIG. 12 is an isometric view of a container according to the presentinvention having a shape of an inverted truncated rectangular pyramid;

FIG. 13 is an exploded isometric view of only a top portion of acontainer according to the present invention with a rectangularreinforcement frame provided with integral elongate studs projectingdownwards;

FIG. 14 is an exploded isometric view of only a top portion of acontainer according to the present invention with a rectangularreinforcement frame provided with a box-like support structure;

FIG. 15 is an isometric view of a container according to the presentinvention in which the top base is smaller than the rectangular base;

FIG. 16 is an isometric view of a container according to the presentinvention formed with a narrowing middle portion;

FIGS. 17(a)-(d) are isometric exploded views of different means forsealing or closing the top of the container;

FIG. 18 is an isometric view of another embodiment of a containeraccording to the present invention;

FIG. 19 is an isometric view illustrating a modification of a containeraccording to the present invention;

FIG. 20 is an isometric partial view of a step in obtaining a baseaccording to a modification of the invention;

FIG. 21 is an isometric partial view of the modification as in FIG. 20;

FIG. 22 is a perspective view depicting a continuous manufacturerprocess of a container in accordance with an embodiment of the presentinvention;

FIG. 23(a) is a perspective view depicting one process for preparing apouch for the manufacture of a container according to the presentinvention;

FIGS. 23(b)-(g) are schematic cross-sections through different stages ofthe process of FIG. 23(a);

FIG. 24(a) is a second process for preparing a pouch for the manufactureof a container according to the present invention;

FIGS. 24(b)-(d) are schematic cross-sections through different stages ofthe process of FIG. 24(a);

FIG. 25(a) is a perspective view depicting the manufacture of a pouchaccording to a third process for the manufacture of a containeraccording to the present invention;

FIGS. 25(b)-(d) are schematic cross-sections through different stages ofthe process of FIG. 25(a);

FIG. 26(a) is a perspective view depicting the manufacture of a pouchaccording to still a different process, for the manufacture of acontainer according to the present invention; and

FIGS. 26(b)-(e) are schematic cross-sections through different stages ofthe process of FIG. 26(a).

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

Reference is first made to FIGS. 1 and 2 of the drawings in which twosheets 1 and 2 of substantially the same size are positioned facing eachother where the facing surfaces of the sheets are made of or coated witha heat weldable material such as polyethylene.

A third sheet 3 has the same width as that of sheets 1 and 2 and is madeof or coated on both faces with a heat weldable material. The thirdsheet 3 is folded into two and is then placed between the two sheetswith its bottom edges 4 aligned with the bottom edges 5 of sheets 1 and2 and the fold line 7 between the sheets 1 and 2.

Alternatively, a single sheet of material made of or coated on bothfaces thereof with a heat sealable material is used instead of saidthree single sheets 1, 2 and 3 as can readily be understood andillustrated in FIG. 1 by the dashed lines.

Then the lateral edges 6 of the sheets 1 and 2 are welded as known perse, sandwiching the lateral edges 8 at the folded sheet 3.

At a second step the bottom edges 5 of sheets 1 and 2 are welded torespective bottom edges 4 of sheet 3. Welding of the two bottom edges 4to one another is prevented by first inserting therebetween a plate 9coated with a non adhering material such as Teflon™ or silicon, prior tothe welding process. At the end of this process a pouch generallydesignated 11 is formed.

Reference is now being made to FIGS. 3-5 illustrating how therectangular base is formed. A rectangular core member 15 is providedwith members 16 and 17 laterally expandable in two perpendicular axesand coated with a non adhering material. The core 15 is then insertedinto the pouch 11 and is pushed down until a central portion of thethird sheet 3 becomes substantially flat at the bottom of the pouch 11whereby, a flat rectangular base 20 is formed.

As seen in FIG. 5, after this step is completed, side walls 18 areformed as well as two overlapping triangular portions 19 formed out ofthe third sheet 3 at each side of the container and which partiallyoverlap the side walls 18. The elements 16 and 17 of the core member 15are then expanded as seen in FIG. 4 so as to snugly fit at the bottom ofthe pouch, pressing the triangular portions 19 against the side walls18.

In order to fix the rectangular shape of the base, the triangularportions 19 must be welded to the side walls 18. Heat is applied to thetriangular portions by electric thermal pads 21 as known per se and ifrequired also from thermal elements within core 15 (not shown). Afterthe expandable members 16 and 17 are retracted, the core 15 can beremoved from the pouch and a self-standing rectangular base containeraccording to the present invention is obtained.

In accordance with another embodiment shown in FIG. 6, a reinforcementelement 22 is made of or coated with a heat sealable material and whichin the particular embodiment has a rectangular frame shape fitted forwelding to the bottom surface of the rectangular base 20 in a manner aswill hereinafter be explained in detail. As seen, the reinforcementmember has an inverted L-shaped cross-section for supporting aperipheral portion of the base. Alternatively it may be provided withstrengthening ribs or may be a flat surface or even consists of fourindividual right angled members.

FIG. 7 schematically illustrates how the reinforcement element 22 isattached to the container's base. A first expandable rectangular core 15as explained with reference to FIG. 4 is inserted into the container anda second similar expandable rectangular core member 15′ is positionedunder the reinforcement element 22. Then the cores 15 and 15′ areexpanded and pushed against one another whereby the reinforcement memberis brought into position with respect to the container, with heatapplied by electric thermal pads 21, whereby the reinforcement elementis welded to the container as already explained. Heat may also beemitted by heat pads integral with the core members 15 and 15′.

FIG. 8 illustrates one embodiment of sealing the container by weldingthe top edges of the front and rear walls 1 and 2. In this way thecontainer maintains its rectangular base shape.

FIGS. 9 and 10 show how the container is sealed by welding the top edgesof the side walls 18 obtaining the special shape as seen. The dashedline 19 illustrates a tear-line for pouring liquid.

Referring now to FIG. 11 there is shown a top rectangular portion of acontainer 11 and a rectangular reinforcement frame element 25. Thereinforcement frame 25 is made of or coated with a heat weldablematerial and when assembled it snugly fits within the container flushwith the top edges and is then welded thereto, whereby the top edge ofthe container acquires the shape of the reinforcing element and becomesfirm and will not deform.

However, it should be obvious that any size and shape of reinforcementelement 25 may be used as long as it can be securely welded to the topedges of the container. It should also be obvious that the reinforcementelement may be made of or coated with a heat sealable material aspreviously explained, or it may be made of metal or other suitablematerial which may be secured to the container by folding it over thetop edges of the container and clampingly attaching it or by other meansas known per se.

In FIG. 12 a container 11 is formed as already explained with the sheets1 and 2 made of a material which may be stretched under heat such aspolyamide and which sheets are coated or laminated with a heat weldablematerial. Then, an expandable core having a cross-section of arectangular pyramid (not shown) is fully inserted into the container andis expanded until its side plates are pressed against the inner walls ofthe container. Then the expanded core is heated by internal thermalelements (not shown) to a temperature suitable for plastic deformationof the laminate constituting the walls of the container. It is thenslowly drawn out of the container while gradually expanding thecross-section of the core, resulting in that the container acquires ashape of an inverted truncated rectangular pyramid as seen in FIG. 12.

Alternatively the rectangular pyramid-shape may be formed in a hotenvironment instead of applying direct heat to the container, forexample, in an oven or in a hot air tunnel or in a combination thereof.

Then a rectangular reinforcement frame element 25′ having a largerprojection than the rectangular base 20 is welded to the top edge of thecontainer as seen in FIG. 12, imparting the container's rigidity.

The container seen in FIG. 12 is suitable for stacking within similarsuch containers, thereby reducing storage space required for such emptycontainers.

FIG. 13 illustrates how a reinforcement element 27, made of or coatedwith a heat sealable material, is integral with four reinforcement studs28 projecting downwards from the corners of the frame. The studs 28 arealso made of or coated with a heat sealable material and aresubstantially as long as the inner length of the container. The frame 27with the integral studs 28 is inserted into the container 11 and iswelded to the container by applying heat and pressure thereto by meansof an expandable core (not shown), as already explained.

In accordance with another embodiment of the present invention, alsoseen in FIG. 13, a second reinforcement frame 30 is integral at anopposed end of the studs 28 parallelly disposed with respect to the topreinforcement frame 27, whereby improved rigidity is obtained.

Once the studs 28 are welded to the container, the latter becomesreinforced in its axial direction too, retaining its rectangularbox-like shape even if it is crushed while empty.

FIG. 14 differs from FIG. 13 in that instead of the four studs 28 thereinforcement element 27 is integral with a reinforcement box-likestructure made of or coated with a heat sealable material and suitablefor inserting into the container 11 abutting with the walls of thecontainer. Preferably the reinforcement box-like structure 29 is weldedto the walls of the container but this is not compulsory.

FIG. 15 of the drawings illustrates a container with narrowing walls.After forming the container 11 as already explained, the straight edges29 (illustrated by dashed lines) are reformed along a concave line 31which may as well be straight or other lines. The edges are welded alonglines 31 by means of hot pressure plates (not shown) obtaining thenarrowing shape of the container. Then reinforcement frame 32 is weldedat the top of the container as previously explained and the excessivewelded flaps 33 may be cut adjacent the welding line 31 for pleasing theeye.

FIG. 16 shows a container with a narrowing portion 36 along thecontainer, whereby new corner edge 37 is produced by pinching andwelding together respective portions of the side walls with the adjacentfront and rear walls, similar to the embodiment of FIG. 15 and ifrequired removing the excessive portions 36.

FIG. 17 illustrates several means for sealing or closing the top of thecontainer. In FIG. 17(A) a frame 41 made of or coated with a heatsealable material is provided with a nozzle 42 which frame 41 is weldedor attached to frame 25 as previously discussed. The contents of thecontainer is consumed through nozzle 42 which may be closed by asuitable seal. In FIG. 17(B) there is an aluminum foil 43 embeddedwithin a frame 44 made of or coated with a heat sealable material whichsnugly fits within frame 45. The frame 44 is welded to frame 45, wherebythe container is sealed. When it is desired to consume the contents ofthe container, then the aluminum foil 43 is cut adjacent frame 44 andremoved whereby a suitable plastic cover may be provided for repeatablesealing and closing of the container.

In FIG. 17(C) the container is sealed by cover 46 provided with a nozzle47, whereby the cover 46 is directly welded or otherwise attached to thecontainer 11 omitting the use of a reinforcement frame 45.

In FIG. 17(D) a foil 48 made of aluminum or any other material suitablefor sealing and having an integral frame 49 is directly welded to thetop edges of container 11, omitting the use of frame 45 as in FIG.17(C). It should be obvious that the cover may be attached to thecontainer by any other suitable means as known per se.

In FIG. 18 another embodiment of a container is seen in which the sidewalls 18′ consist of a substantially flat portion 51 and a gussetportion 52 consisting of two overlapping flaps 53 and an intermediateportion 54.

FIG. 19 shows how the container is manufactured in the shape of a jugformed with a handle portion 56 and a pouring mouth 57. The handleportion is made by forming a gusset portion as in the embodiment of FIG.18 and welding the overlapping flaps 53′ to one another. Thereafter, anopening 58 is cut out in each of the flaps 53′, said openings servingfor gripping the container.

FIGS. 20 and 21 illustrate the steps of reinforcing the base portion ofthe container according to another embodiment of the invention. Afterthe container is complete as seen in FIG. 5, instead of attaching areinforcement member 22 (as in FIG. 6), a slot 60 is cut at each cornerof the base skirt 61. Then, the portions of the skirt are folded inwardas indicated by arrows 62 and are welded to the bottom face of the basemember 20, whereby the base becomes stiff and durable.

Attention is now directed to FIGS. 22 to 26 schematically depicting thestages of a process for manufacturing a container according to thepresent invention, comprising also filling and sealing means.

Various manufacturing stages and components of the container are thesame as those of FIGS. 1 to 5 and accordingly, like elements andcomponents are given the same reference numerals as the correspondingones in FIGS. 1 to 5 with a prime indication, and the reader is referredto those previous figures for a detailed explanation.

FIG. 22 depicts a schematic layout of a continuous process forpreparing, filling and sealing a container according to the presentinvention.

A first step generally designated 70 is preparing a pouch 11′. Severaldetailed examples of this step will be specified hereinafter.

The prepared pouch 11′ then approaches a rotating work site generallydesignated 72 and comprising gripping means 74 which may be, forexample, vacuum pads as known per se. Then, at 76 the pouch 11′ isexpanded by suction means separating the sheets 1′ and 2′ from oneanother.

The next step indicated 78 comprises inserting an expandable core 80into the pouch and at station 82 a central portion of the bottom sheetof the pouch is unfolded so that the unfolded portion assumes itsrectangular shape and the two peripheral portions form two overlappingtriangular portions as explained. Finally, two welding pads 84 laterallyapproach the container and weld the two overlapping triangulares inorder to fix the container's shape, as hereinbefore explained.

Further, working stations may be added to the assembly 72, e.g. foradding reinforcement elements, special configuration of the container,etc. as already explained hereinabove. The work site 72 then dischargesthe container over a conveyer belt 86, advancing the ready container toa filling station 88 for automatically filling as known per se.

Then, the filled containers progress over the conveyor belt towards asealing site generally designated 90, wherein the containers are grippedby suitable arms 92 and introduced into a sealing station 94, whereinthe containers are sealed, e.g. by welding the top edges as illustratedin FIG. 8 or by any other suitable sealing means as described withreference to FIGS. 9, 10 or 17 or otherwise.

At the end of this step, the containers are ready for consuming and areconveyed by conveyor 96 to a packing station (not shown).

Referring now to FIGS. 23(A) to (G), there is seen the first step of theprocess, generally designated 70 in which a pouch 11′ is prepared.

A first film 100, having a top surface 102 coated with a heat weldablematerial, released from an unwinding roller 104. Simultaneously, asecond film 106, having both faces 106′ and 106″ thereof coated with aheat weldable material, is dispensed from an unwinding roller 108,centrally positioned over the first film 100 (as seen in FIG. 23(C)).

The central portion of the film is then sucked into a recess 109 at anedge of a triangular-shaped forming member 110 (better seen in FIGS.23(B) and (E)).

The films positioned by pulleys 112 and 114 pass over a blade 116,whereby the films are cut along their bottom edge and the cross-sectionof the films now resemble that presented in FIG. 1 of the drawings.

Two hot rollers 118 are positioned juxtaposed one another with anon-adhering plate (e.g. Teflon™ or silicon) 120 positionedtherebetween. As the films travel between the rollers 118, the bottomedges 4′ and 5′ of the sheets are welded and as the laminate passesbetween rollers 122 it is welded by the hot welding ribs 124, whereby aplurality of joined pouches 126 are produced, which are then separatedat a cutting station 128 as can be understood.

In FIGS. 24(A) to (D), two sheets 130 and 132, having their facing faces130′ and 132′ coated with a heat weldable material, are dispensed fromunwinding rollers 134 and 136, respectively. A third sheet 138, havingboth faces 138′ and 138″ heat weldable, is dispensed from unwindingroller 140.

Before approaching the facing films 130 and 132, the third film 138 isfolded in two by a grooved triangular member 142 as explained withreference to FIG. 23(B). The folded sheet 138 (forming the base sheet)and sheets 130 and 132 (forming the walls) then progress via positioningpulleys 144 and 146 and their bottom edges are welded by welding rollers148, with an un-weldable plate 150 introduced therebetween as alreadyexplained.

Then the laminate is welded by welding ribs 152 of rollers 154 wherebythe side edges of the pouches are formed. Finally the pouches 126′ areseparated from one another as explained hereinabove.

FIGS. 25(A) to (D) illustrate a process essentially similar to that ofFIGS. 24(A) to (D), with the exception that a reclosable zipper-likestrap 156 is welded to the top edges of the pouch by welding rollers 158and a non-welding plate 160 introduced between the sheets. The pouchesand containers later prepared by this process can thus be closed andopened many times as can be appreciated.

FIGS. 26(A) to (E) illustrate how a pouch useful in preparing acontainer according to the present invention may be prepared from asingle sheet 162 having both faces 162′ and 162″ heat weldable andreleased from an unwinding roller 164. The film sheet 162 travelsbetween a block member 166 having an essentially W-like cross-sectionand between a triangular cross-shaped gliding member 168, graduallyforming the film to a shape as seen in FIGS. 26(B) and (C), so that whenthe film reaches the positioning pulleys 170 it has already obtained theconfiguration illustrated in FIG. 1 (with the dashed line). From here onthe process continues as already explained with reference to FIGS. 23 to25.

It should be obvious to a person versed in the art that any combinationof the above embodiments may be carried out mutatis mutandis.

What is claimed is:
 1. A container having a base with a front edge, arear edge and side edges, and walls extending upwardly therefrom; thebase being generally rectangular and being made of a laminated filmhaving an inner face and an outer face, both said inner and outer facesbeing heat weldable, and the walls being made of a laminated film havingan inner face and an outer face, only said inner face being heatweldable; said walls and said base of the container being constructedfrom a front sheet having a bottom edge, a top edge and lateral edges, arear sheet having a bottom edge, a top edge and lateral edges, and abottom sheet, respectively; the bottom sheet being folded along amidline thereof thereby having a first flap and a second flap connectedtogether at said bottom sheet midline, said flaps extending downwardsfrom said midline, said flaps each having a bottom edge and lateraledges, and wherein the bottom edge of said first flap is joined to thebottom edge of the front sheet and the bottom edge of the second flap isjoined to the bottom edge of the rear sheet; wherein the lateral edgesof the front sheet and the rear sheet are welded to one another withbottom portions of the lateral edges of the front and rear sheetssandwiching corresponding lateral edges of the first and second flapstherebetween; wherein the bottom sheet is unfoldable into asubstantially rectangular shape to form said base, with central parts ofthe bottom edges of the flaps of the bottom sheet forming the front andrear edges of the base and with first and second peripheral portions ofthe bottom sheet each forming a pair of corresponding overlappingtriangular portions having lower edges thereof defining the side edgesof the base, and side walls extending from said side edges of said basewith the welded lateral edges of the front and rear sheets being atabout a midline of the side walls; said container being fixed by weldingeach of the pairs of corresponding overlapping triangular portions toeach other and to the side wall adjacent said triangular portions atleast along a part of a bottom edge portion thereof.
 2. A containeraccording to claim 1, wherein one or more reinforcement elementscomprising a heat weldable material are welded to a bottom face of thebase.
 3. A container according to claim 1, further comprising closuremeans provided along said top edges of said front and rear sheets, saidclosure means being selected from the group consisting of a seal formedby connecting the top edge of said front wall to the top edge of saidrear wall and a seal formed by connecting top edges of said side wallsto one another.
 4. A container according to claim 3, wherein saidclosure means is reusable to provide for a plurality of closing andopenings.
 5. A container according to claim 1, comprising at least onereinforcement element attached to at least the top edges of the frontand rear sheets.
 6. A container according to claim 5, wherein saidreinforcement element is adapted for receiving a sealing or closingarrangement.
 7. A container according to claim 5, wherein saidreinforcement element further comprises a second, heat weldablereinforcement structure, and wherein said second reinforcement structureis welded to the walls of the container.
 8. A container according toclaim 5, wherein said reinforcement element has a first projection,wherein said base has a second projection, and wherein said firstprojection is different than said second projection.
 9. A containeraccording to claim 5, wherein said reinforcement element issubstantially larger than said rectangular base, and wherein thecontainer tapers inwardly to said rectangular base.
 10. A containeraccording to claim 1, comprising generally stiff elongated studscomposed at least in part of a heat weldable material, said studs beingwelded to the walls of the container.
 11. A container according to claim1, further comprising a handle formed in a first portion of saidcontainer, and a pouring mouth formed in a second portion of saidcontainer, wherein said first section of said container is opposite saidsecond section of said container, and wherein said handle furthercomprises an opening formed from at least three holes provided in saidfront sheet and said rear sheet.
 12. The container as claimed in claim 1wherein said laminated film with both said inner and outer faces heatweldable comprises a heat-weldable plastic material.
 13. The containeras claimed in claim 1 wherein said laminated film with both said innerand outer faces heat weldable comprises a plastic material with aheat-weldable coating laminated to each of said inner and outer faces.14. The container as claimed in claim 1 wherein said laminated filmhaving only said inner face heat weldable comprises a plastic materialwith a heat-weldable coating laminated to said inner face.
 15. A processfor the manufacture of a container, the container having a generallyrectangular base and walls extending therefrom, the base being made of afirst laminated film having an inner face and an outer face, with bothof said faces being heat weldable, and the walls being made of a secondlaminated film having an inner face and an outer face, with only saidinner face of said second laminated film forming said walls being heatweldable, the process comprising: (a) constructing said container from afront sheet having a bottom edge and lateral edges, a rear sheet havinga bottom edge and lateral edges, and a bottom sheet, the bottom sheetbeing folded along a midline thereof with first and second flapsextending downwards from the midline, said flaps each having a bottomedge and lateral edges, and wherein the bottom edge of the first flap isjoined to the bottom edge of the front sheet and the bottom edge of thesecond flap is joined to the bottom edge of the rear sheet; and weldinglateral edges of the front and rear sheets to one another with bottomportions of the lateral edges of the front and rear sheets sandwichingcorresponding lateral edges of the first and second flaps; (b) unfoldingthe bottom sheet such that a central portion of the sheet assumes arectangular shape and two peripheral portions of the bottom sheet formtwo overlapping triangular portions; and (c) welding the two overlappingtriangular portions to one another and welding a peripheral triangularportion of the two triangular portions with a juxtaposed inner face of acorrespondingly juxtaposed front and rear sheet.
 16. A process accordingto claim 15, further comprising welding a reinforcement element composedat least in part of a heat weldable material to a bottom face of thebase.
 17. A process according to claim 15, further comprising sealingsaid top edges of said front and rear sheets, said sealing step beingselected from the group consisting of welding the top edge of said frontwall to the top edge of said rear wall and welding top edges of saidside walls to one another.
 18. A process according to claim 15, furthercomprising attaching at least one reinforcement element to at least thetop edges of the front and rear sheets.
 19. A process according to claim15, comprising welding generally stiff elongated studs composed at leastin part of a heat weldable material, to the walls of the container. 20.A process according to claim 15, further comprising forming a handlestructure at one wall section and forming a pouring mouth at an opposedwall section, wherein forming said handle structure further comprisesproviding at least three holes in said front and rear sheets.
 21. Acontainer having a rectangular base formed out of a first laminated filmsheet having an inner and an outer face, and a front, a back and twoside walls formed out of two second laminated film sheets, said twosecond laminated film sheets each being welded to one another along sideedges thereof and sandwiching therebetween at a bottom portion,corresponding side edges of said first laminated film sheet which isfolded downward about a midline thereof in a direction transverse tosaid side edges of said first laminated film sheet; a bottom edge ofeach of said two second laminated film sheets being welded to acorresponding bottom edge of said folded first laminated film sheet;both an inner and an outer face of said first laminated film sheet, andonly an inner face of each of said two second laminated film sheetsbeing heat weldable; the container has at each side wall two overlappingtriangular portions being formed during a forming step out of said firstlaminated film sheet with a base of each triangle defining a side edgeof the container's base, whereby front and rear edges of the container'sbase extend between said side edges, said forming step being done by amandrel being inserted into a space defined between said welded twosecond laminated film sheets, the mandrel opening said container bypressing said first laminated film sheet in a downward direction andpressing said two second laminated film sheets outwardly in twogenerally opposite directions orthogonal to the downward direction; thestructure being fixed by welding the two overlapping triangular portionsat each side wall to one another and to the adjacent correspondingportions of said two second laminated film sheets which become the sidewalls of the container.
 22. A container as claimed in claim 21, whereinan inner portion of each of said overlapping triangular portions is madeout of said first laminated film sheet and an outer portion is made outof said two second laminated film sheets.
 23. The container as claimedin claim 21 wherein said first laminated film sheet comprises aheat-weldable plastic material.
 24. The container as claimed in claim 21wherein said first laminated film sheet comprises a plastic materialwith a heat-weldable coating laminated to each of said inner and outerfaces.
 25. The container as claimed in claim 21 wherein each of said twosecond laminated film sheets comprises a plastic material with aheat-weldable coating laminated to said inner face.
 26. A process forthe manufacture of a container having a rectangular base, the processcomprising: a. providing a laminated first film having a first andsecond side, the first side being heat weldable and the second side notbeing heat weldable, said first film having a transverse leading edge, atop edge, and a bottom edge; b. providing a laminated second film havinga first and second side, the first side being heat weldable and thesecond side not being heat weldable, said second film having atransverse leading edge, a top edge, and a bottom edge; c. providing alaminated third film having a first and second side, both the first andsecond sides being heat weldable, said third film having a transverseleading edge, a top edge, and a bottom edge; d. folding said laminatedthird film in a longitudinal direction intermediate said top and bottomedges along a fold line so as to form a first flap and a second flap,such that said top and bottom edges of said laminated third film arejuxtaposed each other, said first and second flaps being joined at oneends thereof at said fold line such that said bottom edge of saidlaminated third film becomes a bottom edge of said first flap, and saidtop edge of said laminated third film becomes a bottom edge of saidsecond flap; e. placing said heat weldable first sides of said laminatedfirst and second films facing each other with respective transverseleading, top, and bottom edges in corresponding mutual alignment; f.inserting said folded laminated third film between said laminated firstand second films with said bottom edges of said first and second flapsin alignment with said bottom edges of said laminated first and secondfilms so that said fold is oriented towards a middle portion of saidfirst laminated film and oriented towards a middle portion of saidsecond laminated film, and the transverse leading edge of said laminatedthird film is in corresponding mutual alignment with the leading edgesof said laminated first and second films; g. in any order heat welding abottom edge portion of said first flap to a bottom edge portion of saidlaminated first film; heat welding a bottom edge portion of said secondflap to a bottom edge portion of said laminated second film; heatwelding a first transverse portion of said laminated first film, whichextends from said bottom edge to said top edge thereof, to a firsttransverse portion of said laminated second film, which extends fromsaid bottom edge to said top edge thereof, including simultaneously heatwelding a first transverse portion of said first flap and a firsttransverse portion of said second flap to each other and to bottomportions of said first transverse portions of said laminated first andsecond films; heat welding a second transverse portion of said laminatedfirst film, which extends from said bottom edge to said top edgethereof, to a second transverse portion of said laminated second film,which extends from said bottom edge to said top edge thereof, includingsimultaneously heat welding a second transverse portion of said firstflap and a second transverse portion of said second flap to each otherand to bottom portions of said second transverse portions of saidlaminated first and second films; h. cutting off a section of saidlaminated first, second and third films along a transverse cut-lineproximate to a position of a heat-weld disposed along said secondtransverse portions of each of said laminated first, second and thirdfilms, whereby a first edge of said cut corresponds to a trailing edgeof a first container blank, and a second edge of said cut corresponds toa leading edge of a next container blank and thereby simultaneouslybecomes the leading edge of each of the laminated first, second andthird films; i. drawing apart portions of the non-welded portions ofsaid cut-off laminated first film section and said cut-off laminatedsecond film section; j. inserting a mandrel having spreadable jawsbetween said drawn apart portions of said laminated first film and saidlaminated second film; k. spreading said jaws of said mandrel to spreadapart said laminated first film and said laminated second film so as toform two sets of two triangular portions on each side thereof from saidfirst and second flaps; l. heat welding each set of said triangularportions together at least along a bottom portion thereof, and heatwelding each set of said triangular portions to juxtaposed first sidesof said laminated first and second films; wherein step h can beperformed in any order in relation to steps d-g; whereby a containerhaving a flat rectangular bottom is formed.
 27. The method as claimed inclaim 26 and further including feeding a laminated single film that hasa leading edge and a longitudinal axis, splitting said single film alonga longitudinal midline so as to provide said laminated first film andsaid laminated second film.